Grinding machine



Dec. 17, 1935. F. M. GERTISER 2,024,283

GRINDING MACHINE Filed March 1, 1935 5 Sheets-Sheet 1 fkA /YA 6207/55? Gamma/1 Dec. 17-, 1935.

F. M. GERTISER GRINDING MACHINE Fiied March 1, 1955 5 Sheets-Sheet 2 5 Sheets-Sheet if Dec. 17, 1935.-

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rfFm/rm 617/756? Dec. 17, 1935. F. M. GERTISER 2,024,233

GRINDING MACHINE Filed March 1, 1953 5 Sheets-Sheet 5 Patented Dec. 717, 1935 PATENT OFFICE GRINDING MACHINE Frank-M. Gertiser, Detroit, Mich assignor to.

Cincinnati Grinders Incorporated, Cincinnati, Ohio, a corporation of Ohio Application March 1; 1933, Serial no. 659,215

1'1 Claims. (0!. 51-103) 7 This invention relates to improvements in machine tools and especially to improvements in grinding machines of the centerless type.

An object of this invention is the provision of .an improved grinding machine for producing irregular shaped work pieces, particularly relieved or oval pistons, as employed in internal combustion engines.

Another object of the invention is the provision of a simple machine that will not readily become out of order and yet will produce the work pieces above indicated in an expeditious manner and. within accurate limits.

A further object or" the invention is the provision of a machine of this type so designed as to insure successive work pieces being identical in all respects.

A still further object of the invention is the provision of a grinding machine for relieving in ternal combustion engine pistons that is auto= matic or semi-automatic in its functioning, re-

quiring the operator only tomanually replace the work and initiate the cycle of operation.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification considered in conjunction with the accompanying drawings, forming a part thereof, and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention. v In the drawings: I

Figure 1 is a front elevation of a grinding machine embodying the improvements of this in? vention. t

Figure 2 is an end elevational view of the ma- "chine shown in Figure l, and as seen from line 2-2 on Figure l. 1

Figure 3 is a horizontal sectional view taken substantially on the line 3-3012 Figure 1.

Figure 4 is a fragmentary developed plan of a clutch employed in the driving train and forming a detail of the invention.

'onunes-aorrlgures.

' and sharpening same.

Figure 9 is a sectional view through the feed and cycle control mechanism, as seen from line 9-9 on Figure 1, a sectional view of the prime mover therefore being omitted.

Figure 10 is a view taken on line Ill-l0 of Fig- 5 ure 9 illustrating the control cam in elevation.

Figure 11 is a view at right angles to Figure 10, as seen from line I i-l i on Figure it. I

Figure 12 is a horizontal sectional view through the pressure roller as seen from line lZ-IZ on Figure 6 and forming a detail 0! the invention.

Figure 13 is a. fragmentary sectional view through the stopping mechanism as seen .from line 53-93 on Figure l. 1

Figure 14 is a view partly in section and partly 1a in elevation taken on line gilt-Iii of Figure 9.

Figure 15 is an enlarged diagrammatic development of the work rotation control and feeding mechanism.

e 16 is a dlagratic view of an electri- 30 cal circuit'for controlling the machine cycle.

Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts. I

A machine of this invention may comprise a 35 bed so having rising therefrom a pedestal bearing it in which is iournaled aspindle 22 for a, grinding wheel 23. The spindle 22 and grinding wheel 23 are adapted to be rotated at a high rate of at in a cloc direction. The bearing 28 30 terminates in a hood that encloses a grinding wheel 23 from which hood projects a support 2 for a truing mec it 25 adapted to be actuatedacross the face of the wheel 23 for truing The bed 20 is further provided on its upper surface with a dove-tailed guide 26 received in a correspondingly shaped guideway formed in a slide 2?, The slide 2'5 is in turn provided on its upper surface with a dove-tailed guide 28 likewise received in a .condingly shaped guideway formed on an upper slide 2%. The slide 29 is in efiect a housing which encloses mechanism for controlling the rotation of the ,work and for effecting the relativefeed thereof toward and from the grinding wheel.

The work to is, as was above noted, a piston as employed in internal combustion engines and is adapted to have the skirt thereof at diametrical points relieved or undercut leaving the remaining portion of the piston cylindrical. The work, as shown in; Figures 1 and 6, is supported by a pair of work rest blades 39 and 32 respectively secured in slots 38 and 34 formed in a work rest block or bracket 35 secured to the inner edge of w a pilot or hand wheel 5|. 1

the lower slide 21. The blades 3| and32 are each provided with an inclined supporting surface 36 inclining toward one another for thereby forming a work receiving trough in which the work is deposited while in contact with the operative face of the grinding wheel.

The work is backed up at a point substantially diametrical to that, contactedby the grinding wheel with a' rotatable feed wheel 31'which in efiectis a multiple'lobed cam which willbe described in detail later. The wheel or cam 31 .is secured to a spindle 38 journaled in anti-friction bearings 39 and 48 supported by bearing bosses 4| and 42 of the housing 43 secured in any desirable manner to the slide or housing 29. The spindle 38 is adapted to be rotated at a relatively slow rate of speed in a clockwise direction and in timed relation with the rotation of the work. In fact, the wheel or cam 31- and the work 30 are rotated at the same peripheral speed whereby they are in effect geared to one another for a purpose that will later appear.

In order to set up the machine for difierent sizes or kinds of work the upper and lower slides- 21 and 29 are adapted to be independently actuated, while during actual practice they are simultaneously shifted. For this purpose there is provided aclamp 44, see Figure 1, whereby the slides are clamped to one another for unitary movement while the lower slide carries clamps 45 which when operated to clamping position secure the said lower slide against movement, while permitting independent movement of the upper slide relative thereto. In order to adjust these slides whether independently or as a unit relative to the bed, the upper slide or housing 29 has secured therein a sleeve nut 46, see Figure 3, that'meshes with the screw threads 41 of anadjusting screw 48. The screw48 extends through and beyond the automatic feed and control mechanism enclosed within housing 49 secured to a projecting lug or ledge 58 of the bed 28. For rotating the screw 48 it has secured to its projecting end "be of any well-known type and terminates in the final driven shaft 54 which projects beyondthe bed and carries as'procket 55 about which is trained a sprocket chain 58. The sprocket chain. 56 extends upwardly along the rear of the bed 28 and is enclosed within a housing or guard 51 and is in turn trained about the sprocket 58 keyed or otherwise secured to a shaft 59, -journaled in the slide or housing 29. Also keyed or otherwise secured tothe shaft 59 is a pair of different sized pinions or gears and GI, the former or larger. gear meshing with a'gear 82 keyed to a transverse shaft 83, while the latter -or smaller gear meshes with a larger gear 64 loosely journaled on the said shaft 63. From this it will be seen that the shaft 53 is rotated at a faster rate of speed than the gear 84. Keyed or otherwise secured to the ear '84 for rotation therewith is a chain.spro'cket about which is trained achain 58 in turn trained about alarger sprocket 61 keyed or otherwise secured to the spindle 38- intermediatethe bearings 39 and 40.

10 operation of the clutch will be described in detail later.

the arbor 18. The arbor 18 is journaled in the 20v bracket 15 and projects forwardly into the grinding throat formed by the proximate portions of the grinding wheel and backing up or cam wheel 31. The inner end of the arbor 18 is provided with a forked member 19 having the fingers 5 thereof encircling a dummy wrist pin 89 passing through the wrist pin holes or bores in the work 38.

From the foregoing it will be seen that the spindle 38 is rotated at a lower speed or R. P. M. than the arbor 18, but due to the ratios between the several gears and sprockets, the work and backing up or cam wheel are infact rotated at the same peripheral speed. although at different R. P. M.s. This ratio is such that the work 35 makes three revolutions to but a single revolution of the backing up or cam wheel 31.

. As will be seen in exaggerated form from Figure 15,- the-cam wheel has in effect six lobes 8|a, 81b, 8|c, 81d, 81c, and 8|) between each pair of which is a receding low portion 82a, 82b, 82c, 82d, 82e, and 82!. From this it wil be seen that two of the lobes engage with the work during each.

' rotation thereof since the said lobes are equally spaced around the periphery of the wheel. From this itrwill be evident that each lobe as it engages 'the work will actuate it towardthe grinding wheel while as the low portions come into play the work will be permitted to fall away from the grindlngwheel and thereby relieve the work at the desired diametrical pointsor portions.

a As was mentioned, above, the work as a whole is automatically brought into operative engagement with the grinding, wheel for which purpose the housing or casing 49encloses the'feed and control mechanism. This mechanism comprises a bearing 83 formed in the casing 49 .through which is axially shiftable a slide block 84. The slide block 84 is secured toa reduced portion 85 of the adjusting screw 48 and said slide block 6 has pivoted to it one end of a pair of pitmans or links 88, the other ends of which are pivoted at 81 to one arm 88 of a bell crank '89. The bell crank 89 is pivoted at the juncture of its arms to one wall'90 of the housing 49 and to a web 9| '1 projecting upwardly from the base of the housing 49. The other arm 92 of the bell crank 89 carries a block 93 fora roller or cam follower 94 received in cam track 95 of face cam 96. The cam track 95 is provided with a rapid rise for rapidly actuating the slides toward the grinding wheel to-cause initial contact between the work and the wheel whereupon a slow rise of the cam track is employed for slowly feeding the work into the grinding wheel. This is followed by a ,It is while in the retracted position that the work is replaced or changed. I

The cam 96 is secured to one end of a shaft 91 rotatably journaled in a bearing provided by the housing 49 and the shaft has secured to it near its other end a worm wheel 98 meshing with a,

worm 99 formed on or secured to a worm shaft I disposed transversely of the housing 49. Secured to the under surface of the housing 49 is a motor or prime mover I0l belted or geared as by a transmission within the guard I02 to the extreme end of the worm shaft I09.

The parts are adapted to make one complete cycle and then stop. For this reason a limit switch is included in the electrical circuit controlling the prime mover IIII. The switch is enclosed within a housing or guard I03, see Figures 9 and 14, from which projects the switch actuating stem I04 The stem I04 is adapted to be engaged by a cam lug I formed on the plate I06 secured in any desirable manner to the cam shaft 91 for rotation therewith. From this it will be seen that each revolution of the cam shaft 9? actuates the switch plunger I04 for closing the stopping switch and thereby breaking the circuit to the motor IIII and stopping'the movement thereof. These parts come into play during the time that the feed cam 96 is in position for completely retracting the work and slides from the grinding wheel.

The electrical circuit for the motor IOE is shown in Figure 16 and illustrates the main line wires I31 and I38 connected with the motor IN by wires I39 and I40. Included in the wires I39 and I49 is amagnetic switch IM having associated therewith the magnetic latch M2 for latching the switch in a closed position. A push button control station is also included in the circuit and comprises a normally open starting switch I43 and. the normally closed stopping switch I4 3. The stopping switch M l might be termed the emergency stop switch as it is only used in case of emergency since the cycle is ordinarily broken by the limit switch "It. In actual practice the push button control station -is mounted on the front face of the machine bed and is contained in a casing or housing I45 to which is pivoted a lever I49 in contact with the starting switch I43. The lever its terminates in knob or plate I41 disposed in position for engagement by the operators knee, thereby leaving his hands free for replacement of the work on the work arbor.

Just prior to the stopping of the motor or prime mover IN the work drive is stopped for thereby stopping the arbor l9 to permit a replacement of the work thereon. As suggested above this stop includes the clutch member Id, shown in developed plan in Figure 4, which has the interrupted camgroove I0? into which the nose I08 of clutch shifter shaft I09 is adapted to be injected. The shaft I09 is in two parts suitably connected by means of a pin and slot 0a,

} and between the two parts of the shaft is a spring H9. The second part I09a of the shaft is provided with a notch receiving the ball end IIE at a lever H2 pivoted intermediate its ends at H3 in the housing or slide 29. .The lever H2 has its other end ball shaped, as at I I4, which is received in a notch in a transverse rod I I5 which extends along the right hand end of the machine and terminates in the short rack II 6, see Figure 13. Meshing with the rack H6 is a pinion II'I keyed or otherwise secured to a shaft II8 projecting. outwardly from the casing 49. The shaft H8 is 'journaled in one wall of this casing as well as in 5 a lug II9 projectingfrom the side of the casing.

Secured in any suitable manner to the shaft H8 is a cam plate or wheel I20 having a single tooth I2I- adapted to engage the hooked end I22 of a slide rod I23 slidable transversely of the housing or casing 49 interiorly thereof. An arm I24 is provided interiorly of the casing 49, being pivoted at I25 to a lug I29 at one end and having a pin and slot connection I21 at its other end with the hooked slide rod I23. Intermediate its ends the arm I24 has projecting from it a lug I23 adapted to engage with cam lug I29 on the rear face of the feed control cam 96. The face or cam track 95 is so related to the cam lug I29 that after the work has been retracted from the grinding wheel and before the switch plunger I04 is actuated, the arm I28 is engaged by the lug I 29 for shift ing the bar H5 and causing the clutch shifter to engage the cam groove I01 and disengage the clutch from the shaft 10 and thereby stop the rotation of the work.

It should be noted that since the clutch member It has but a single tooth I3 and the co-operating' clutch or gear I I has also a single clutch tooth, the arbor '88 will be rotated only when the parts 30 are in a definite relationship so that successive work pieces are produced with the relieved portions the same relative positions with the remaining parts thereof.

In order to hold the work on the work rest blades and in proper'contact with the wheel 31 the work rest block-has'projecting upwardly there from a bracket I30 to which is secured a block I3I by means of a stud I32which passes through a perforation formed in the bracket I30. -Passing through the block IN is a sleeve I33 enclosing a spring pressed plunger I35. The plunger I34 has at its lower end a clevice I35 rotatably supporting a roller I36 adapted to contact with the work, on one side of the center thereof in such a manner as to yieldably urge the work away from the grinding wheel into contact with the-blades 3I and 32 and the wheel or cam 3?.

The operation of this mechanism is as follows:

The arbor and slides are in a retracted position circuit to the magnetic switch IM and thereby starting the rotation of the motor IOI. As soon as this circuit is complete the magnetic latch drops into place and retains the switch in a closed position so that upon release of pressure on the knob Ml, the starting switch then opens. The rotation of the motor I05 rotates the cam 96, first causing the lug I29 on the rear thereof to release the lever I24 so that the clutch ejector rod I09- I991: is withdrawn from the clutch member M thereby permitting its single tooth to be placed in the path of the single tooth of the co-operating clutch member, here shown as the bevel gear. About the time the two teeth are in engagement, the cam 96 has reached the point for shifting the slides and work toward. the grinding wheel. Since the backing up or cam member is constantly rotating, the work is therefore in addition being shifted toward and from the grinding wheel an amount equal to the lobes on said cam and backing member. This continues until the cam Ol reaches its portion for retracting the work, at which time the said work is reduced to the desired size and contour.

As soon as the work has been retracted from the grinding wheel, the clutch ejector rod is inserted in the cam groove therein for retracting the clutch and breaking the drive to the work 1 whe eupon the rotation thereof stops. As soon as the work has stopped the limit switch IN is actuated for breaking the circuit to the magnetic switch and thereby opening said switch and stopping the rotation of the motor, thereby stopping the slides and work in their retracted positions. The operator then replaces the work whereupon he again engages the lever I46 with his knee and initiates a new cycle. a

To compensate for inevitable wheel wear the hand or pilot wheel 5| is periodically advanced and thereby insuring successive work pieces being reduced to the same size and contour.

It is believed that the operation of the improved machine for producing formed work pieces such as relieved pistons will'be readily apparent from the foregoing description. It is to be noted, however, that the mechanism is not to be restricted to the manufacture of relieved pistons, but has equal application to the forming or production of cams and other irregular objects.

' What is claimed is:

1. In a grinding machine of the class described the combination of a bed, a grinding wheel rotatably mounted thereon, means adjacent the grinding wheel for peripherally supporting a work piece while in contact with the wheel, means ior rotating the work while supported, and contoured rotatable means diametrically opposed to the grinding wheel and peripherally engaging the work, said contoured means having successive peripheral elevations and depressions effective against the work whereby, the work is variably urged into operative engagement with the grinding wheel. g

2. In a grinding machine of the class described the combination of a bed, a grinding wheel rotatably mounted thereon, means adjacent the grinding wheel for peripherally supporting a work piece while in contact with the wheel, means for' rotating the work while supported, contoured rotatable means diametrically opposed to the grinding wheel and peripherally engaging the work, said contoured means having successive peripheral elevations and depressions effective against the work whereby the work is variably urged into operative engagement withthe grinding wheel, and means synchronizing the rotation of the work and contoured means.

3.' In a grinding machine of the class described for producing successive work pieces to the same irregular contour the combination of a pair 01' opposed members, one of which is a grinding element operable at a grinding rate of speed and the other a backing up member of irregular contour,

said members forming between them a grinding throat in which the work is disposed, a work support sub-tending the grinding throat for peripherally supporting the work, and means for driving the work and irregular backing up member at the same peripheral speeds for eflecting an intermittent feed of the work with respect to the grinding wheel.

- 4. In a grinding machine of the class described for producing successive work pieces to the same irregular contour the combination of a pair 01 opposed membera'one of which is a grinding element operable at a grinding rate of speed and the other a backing up member of irregular contour, said members forming between them a grinding throat in which the work is disposed, a. work 5 support sub-tending the grinding throat for peripherally supporting the work, means for driving the work and irregular backing up member at the same peripheral speeds for effecting an intermittent feed of the work with respect to the \0 grinding wheel, and means for supporting one of said members together with the work rest blade for unitary movement for operatively associating the work with the other of said members.

5. In a grinding machine of the class described 5 for producing successive work pieces to the same irregular contour the combination of a pair of opposed members, one of which is a grinding element operable at a grinding rate of speed and the other a backing up member of irregular con- 20 tour, said members forming between them a grinding throat in which the work is disposed, a work support sub-tending the grinding throat for peripherally supporting the work, means for driving the work and irregular backing up member at 25 ment operable at a grinding rate of speed and the other a backing up member of irregular contour, said members forming between them a grinding 40 throat in which the work is disposed, a work support sub-tending the grindingthroat for peripherally supporting the work, means for driving the work and irregular backing up member at the same peripheral speeds for effecting an intermittent feed of the work with respect to the grinding wheel, and means supporting one of said members together with the work rest blade for unitary movement for operatively associating the work with the other of said members, said means comprising a cam, power means for rotating the cam, and means for interrupting the power means for the cam at the conclusion of a single cycle.

7. In a grinding machine of the class described the combination of a pair of opposed elements rotatabl-e about axes disposed in parallel planes, one of saidelements being a grinding wheel and the other a work backing member and one of said parts being irregular in contour for intermittently effecting a relative axial approach of the work and grinding wheel for thereby providing an irregular suriace on the work, a work support subtending the grinding throat and peripherally supporting a work piece while contacting the grinding and backing up elements, and yieldable means operable on the work for holding same against the peripheral support and one of the elements.

8. In a work supporting and feeding mechanism for use with grinding machines the combination of a pair or super-imposed slides, a work support on one of said slides for peripherally supporting a work piece, a backing up member in the nature of a multi-lobed cam on the second slide, said work and backing up cam being of different diameters, and means for rotating said backing up member and work at the same peripheral speed-and in timed relation" whereby successive work pieces have their surfaces similarly formed.

9. In a work supporting and feeding mechanism for use with grinding machines the combination of a pair of super-imposed slides, a work support on one of said slides for peripherally supporting a work piece, a backing up member in the nature of a multi-lobed cam on the second slide, said work and backing up cam being of different diameters, and means for rotating said backing up member and work at the-sam'eperipheral speed and in timed relation whereby successive work pieces have their surfaces similarly formed, said means including an arbor for the work mounted on one of the slides, a spindle on the second slide for the backing up member, and transmission means including speed up gearing for rotating the spindle and arbor at different speeds.

10. In a work supporting and feeding mechanism for use with grinding machines the combination of a pair of super-imposed slides, a work support on one of said slides for peripherally supporting a work piece, a backing up member in the nature of a multi-lobed cam on the second slide, said work and backing up cam being of different diameters, and means for rotating said backing up'member and work at the same peripheral speed and in timed relation whereby successive work pieces have their surfaces similarly formed, said means including an arbor for the work mounted on one of the slides, a spindle on the second slide for the backing up member,

transmission means including speed up gearing for rotating the spindle and arbor at different speeds, and a common source of power for the transmission, arbor and spindle.

11. In a work supporting and feeding mechanism for use with grinding machines the combination of a pair of super-imposed slides, a work support on one of said slides for peripherally supporting a work piece, a backing up member in the nature ofa multi-lobed cam on the second slide, said work and backing up cam being of different diameters, means for rotating said backing up member and work at the same peripheral speed and in timed relation whereby successive work pieces have their surfaces similarly formed, and means for cyclically eifecting a relative approach and retraction of the work andwheel one with respect to the other to operatively associate the work and wheel to effect a stock removal from the work and dis-associate same to permit a replacement thereof. 12. In a work supporting and feeding mechanism for use with grinding machines, the combination of a pair of super-imposed slides, a work support on one of said slides for peripherally supporting a work piece, a backing up member in the nature of a multi-lobed cam on the second slide, said work and backing up cam beng of different diameters, means for rotating said backing up member and work at the same peripheral speed and in timed relation whereby successive work pieces have their surfaces similarly formed, means for cyclically ef-'- fecting a, relative approach and retraction of the work and wheel one with respect to the other 2nd means for stopping said means at the com letion of each cycle.

13. In a work supporting and feedingmechthe cycle.

anism for use with grinding machines the commeansfor rotating said backingup member and work at the same peripheral speed and in timed relation whereby successive work pieces have their surfaces similarly formed, means for cyclically effecting a relative approach and retraction of the work and wheel one with respect to the other to operatively associate the work and wheel to eifect a stock removal from the work and dis-associate same to permit a replacement thereof, means for stopping said means at the completion of'each cycle, and means independent of said stopping means for again initiating 14. A grinding machine of the class described for producing relieved pistons for internal combustion engines the combination of a. bed, a grinding wheel rotatably mounted thereon, a.-

work support adjacent the grinding wheel comwork and grinding wheel.

15. A grinding machine for the purpose described including a bed, a. work rest rising from the bed for peripheral engagement with the work to be ground, a grinding wheel disposed at one side of the workrestforoperativeengagement with the work piece when mounted thereon, a rotatable backing up member in the form of a multi-lobed cam disposed at the opposite side of the work rest for-engagement with the work piece whereby the work piece is variably actuated on its rest in the direction of the grinding wheel i accordance with the contour of the multi-lobed cam, a positively driven arbor memher, and flexible drive connections carried by the arbor for engagement with the work piece to effect a predetermined rate of rotation of the work piece whilepermitting its'free floating movement on the support as .determined by the lobes of the cam.

16. A grinding machine for the purpose described including a bed, a work rest rising from the bed for peripheral engagement with the work to be ground, a grinding wheel disposed at one side of the work rest. for operative engagement with the work piece when mounted thereon, a rotatable backing up member in the form of a multi-lobed cam disposed at the opposite side of the work rest for engagement with the work piece whereby the work piece is variably actuated on its rest in the direction of the grinding wheel in accordance with the contour of the multi-lobed cam, a positively driven arbor member,

flexible drive connections carried by the arbor 7 for engagement with the work piece to effect a predetermined rate of rotation of the work piece while permitting its free floating movement .on the support as determined by the'lobes of the cam, and a transmission coupling the arbor and 7 cam for insuring synchronous rotntionthereot in predetermined ratio. 1 y

17. A grinding forth: Pu p se de- -.with-: the work piece when mounted thereon, a

frotatablebacking up member in ,the form 0! s multi-lobed cam disposed at the opposite oi the, work'rest'fo'r engagement-with, work piecewhereby. theworkplece is vsrls actuated on'its rest in the direction of the grinding .wheel in accordance with the contour ot. the multi-lobed cm, a. positively driven'srbor memflexible drive connections carried by the arbor for engagement with the work piece to efi'ect a predetermined rate of rotation of the work.

piece while permitting its free floating movement onthe support as determined by the lobes of the cam, a transmission coupling the arbor and cam for insuring synchronous rotation thereof in predetermined ratio, a clutch member shittable to interrupt the coupled drive bethe cam and-arbor. and means effective 10 the drive connection with a. predetermined relationship between arborand cam, 

